Skeleton to continue the marking guess based exercise.
Here there is the possiblity to test almost all the system mocking io collaborator and the random generator.

Dynamic for the exercise:
make available the empty "walking skeleton" (just with the "Welcome to Master Mind. Please make a guess:" message expectation).

Then proceed with the marker algorithm.
Then when comes the "false double match" help teams to actually move from acceptance to actual unit tests. Then fixing the false double match and so on.

Possibilities: add technical stories like: make the count matches independent from the "present mark as a 'p'/'m' sequence.